<concept id="GUID-68F27C54-A339-507B-9DD3-B3701132FE0A" xml:lang="en"><title>WAP Push Framework Overview</title><shortdesc>WAP Push Framework is a plug-in framework that supports

receiving, processing and storing of WAP (Wireless Application Protocol)

push messages. </shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

<section id="GUID-7E222D54-98DE-460F-98B3-B5CA6709163A"><title>Required background</title> <p>Before using this component,

you must understand <xref href="GUID-9E92EE30-F2E2-5F28-BB2A-391C09EC69D2.dita">ECom Framework</xref> and <xref href="http://www.openmobilealliance.org/" scope="external">Open Mobile Alliance (OMA)</xref> standards. </p> </section>

<section id="GUID-52B5BBB3-74D0-47EA-8FB7-77AA480C73A6"><title>Key concepts and terms</title> <dl>

<dd><p>WAP push messages are specially formatted SMS messages that

display an alert message to the user, and give the user the option

of connecting directly to a particular URL through the mobile phone’s

WAP Browser; for example, notification about a new email. </p> <p>A push message has a header section and a body section. Header section

has <codeph>X-Wap-Application-Id</codeph> and <codeph>Content-Type</codeph> fields. The message body can be any MIME content-type and optionally

encoded. When a push message is received, the framework parses the

message header and loads an appropriate plug-in to process and store

the message in a Message Store. </p> </dd>

<dd><p>The handler (plug-in) supported by the framework are known

as Push plug-in, such as Application Handler or Content Handler. </p> </dd>

<section id="GUID-9EEB2332-6DD1-403A-AF97-4C66AD9B6CE6"><title>Architecture</title> <p>WAP Push Framework provides

support for connectionless (CL) OTA-WSP push. </p> <p>The main components

of the framework are Push Watcher, Application Handler and Content

Handler. A Push Watcher is a plug-in that plug-in to the <xref href="GUID-4603D4ED-966F-5F70-B991-D10495BC2D7E.dita">Messaging Watcher

Framework</xref> and is responsible for listening on the WAP Stack

for incoming push messages. Push Watcher after receiving the message,

loads an appropriate Application Handler through Application Dispatcher.

An Application Handler is responsible for loading the appropriate

Content Handler using the <codeph>X-Wap-Application-Id</codeph> value

to handle the push message and take any action on the message that

may be necessary. However, if a plug-in for a given content-type is

not available, the WAP Push Framework uses the unknown application

handler plug-in (default) and discards the push message. </p> <p>The

following figure shows the architecture of WAP Push Framework. </p> <fig id="GUID-359E967A-EA0E-5AE2-A03C-220EB0C74B38">

<image href="GUID-258FA5F7-5069-5DFE-8F6E-57063064CE65_d0e496901_href.jpg" placement="inline"/>

<dd><p>There are two Push Watchers in the framework for CL OTA-WSP—one

is for secure push and the other is for non-secure push. The insecure

CL watcher is always active and waits asynchronously to receive message

from WAP Stack at port 2948. On receiving a push message, the watcher

wraps the message up in a <xref href="GUID-C52CFBC5-40D0-3B55-B17F-F3709B8D960B.dita"><apiname>CPushMessage</apiname></xref>, parses

the message and calls the Application Dispatcher, passing in the <codeph>X-Wap-Application-Id</codeph> value obtained from the push message. </p> </dd>

<dd><p>The framework contains an Application Dispatcher and a Content

Dispatcher that are used to find the appropriate Application Handler

and Content Handler respectively. </p> <p>Application Dispatcher uses

ECom to load an Application Handler using the application-ID passed

to it by the Push Watcher. Two different Application Handlers are

present in the framework—Unknown Application Handler for applications

of unknown type and User Agent (UA) Application Handler that receives

messages of type ‘<b>x-wap-application:*</b> ’ or ‘<b>x-wap-application:wml.ua</b> ’. The UA Application Handler looks at the content-type of the message

and passes it to the Content Dispatcher. The content dispatcher then

loads an appropriate Content Handler. The Unknown Application Handler

deletes the push message. </p> <p>The Content Dispatcher uses ECom

to load a particular Content Handler (plug-in) based on the content-type

passed in by the Application Handler. The following are the Content

Handlers provided within the framework. </p> <ul>

<li id="GUID-9A90410A-354F-5492-AF7C-562729E12960"><p> <b>SI Content

Handler:</b> These plug-ins process Service Indication (SI) messages.

An SI message is a UA message with content-type <filepath>text/vnd.wap.si</filepath> or <filepath>application/vnd.wap.sic</filepath>. The basic form

of an SI message is a short message with a URI indicating a service;

for example, notification about new emails. </p> </li>

<li id="GUID-63867E1C-1B2A-50E8-9FBE-3C127DA96EEB"><p> <b>SL Content

Handler:</b> These plug-ins process Service Load (SL) messages. An

SL message is an UA message with content-type <filepath>text/vnd.wap.sl</filepath> or <filepath>application/vnd.wap.slc</filepath>. The SL message

contains a URI indicating a service which gets loaded without user

input. </p> </li>

Content Handler:</b> These plug-ins process multipart-mixed messages.

These are messages with content-type <filepath>application/vnd.wap.multipart.mixed</filepath> or <filepath>multipart/mixed</filepath>. They create new sub-messages

from each message part, and load appropriate content handler plug-ins

to process each sub-message. </p> </li>

Multipart-alternative Content Handlers:</b> These plug-ins process

messages for the <filepath>application/vnd.wap.multipart.alternative</filepath>, <filepath>multipart/alternative</filepath>, <filepath>application/vnd.wap</filepath> and <filepath>multipart.related</filepath> content-types. They save

the entire message in the Message Store, where each part is saved

as a child entry to the main part. </p> </li>

<li id="GUID-9AA16C02-F759-541D-B850-719716065F52"><p> <b>Unknown

Content Handler:</b> These plug-ins process content-types for which

there are no handler plug-ins. They store the received push messages

in Inbox of the Message Store. </p> </li>

<section id="GUID-48F54813-3327-45FB-B923-BA6E9C245993"><title>APIs</title> <table id="GUID-F6247FC0-87AC-5F7F-8965-8F10E9B8ACAC">

<section id="GUID-D677C8B2-BFEB-496C-B481-10497537B31C"><title>Typical uses</title> <p>WAP Push Framework is extensible,

that is, new plug-ins can be installed to the framework and installed

plug-ins can be removed from the framework without re-building the

framework. It uses dynamically loaded plug-ins at run-time to support

different content-types; for example, content of push message for

Service Indicator (SI) application. ECom Framework is used to provide

support for run-time loading. </p> <ul>

<li id="GUID-7B03A6BF-D191-568F-8442-5842AC48C2E0"><p>Creating content

handler plug-ins. </p> <p> <b>Note:</b> Push plug-ins must inherit

from the base push plug-in class and override a set of pure virtual

functions. </p> </li>

<li id="GUID-CE7A22B1-D1B2-5CDD-ACF7-9D9FB0A0DC63"><p>Removing any

installed plug-ins. </p> </li>

<link href="http://www.openmobilealliance.org/" scope="external">

<linktext>Open Mobile                 Alliance (OMA)</linktext></link>

<link href="GUID-4603D4ED-966F-5F70-B991-D10495BC2D7E.dita"><linktext>Watcher

Framework</linktext></link>